Hello, Cough, runny nose and other symptoms are usually caused by viral infection. Lots of virus can take hold inside your child nose, mouth, throat or lungs and cause cold symptoms. Cold usually last 10 days in children, but some people have symptoms for up to 2 weeks. Persistent cough should diagnoses for other than the common cold and should considered in children who have cough that is more severe or prolonged than expected with common cold for example, persistant cough for more than 2 weeks without improvement or is worsening. If your daughter has cough persistent for more than two weeks bring her to see a doctor. They may try to find out her severe condition and help her outcome better. Cough may affect the child sleep, school performance, and ability to play. I suggest that airway irritation contributing to cough be relieved with oral hydration, warm fluid, honey or cough candy. Corimic medicine, I normally do not prescribe to a child because it has side effect more than help. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Heang Chan Raksmey, General & Family Physician